I would only bore the minimum ,this will allow you future machining of the block.
I have the carter/webers on my 261 and I'm really impressed with them.
You really don't need a fuel pressure regulator when using carter/webers with a stock fuel pump.
Be ready to spend plenty of cash,they are well worth it.

Plan your work,then work your plan.

1951 3100 Chevrolet
1951 Chevrolet Suburban Carryall
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